Seirus DynaMax Hi-Vis workman cap. It has more warmth, stretch, wicking, and wind block while remaining thin and lightweight. It's ultra thin, stretchy and is built with 6-dart construction for a sleek, comfortable fit. A lightweight, wicking hat, its form-fit design keeps it snug to your head. Reflective stripes were added for maximum nighttime brightness and visibility. Wear it as a thin helmet liner or a weather resistant hat.